Mason Miller

Mason James Miller Bio

Mason James Miller (born August 24, 1998) is an American professional baseball pitcher with the San Diego Padres of Major League Baseball. Nicknamed “The Reaper,” he made his MLB debut in 2023 and earned All-Star honors in 2024. Miller previously played for the Oakland Athletics and currently wears number 22 for San Diego.

Early Life and Background

Miller was born in Bethel Park, Pennsylvania, and attended Bethel Park High School while being homeschooled. He played college baseball at Waynesburg University for four years until graduating, then completed a fifth year as a graduate student at Gardner-Webb University. During his sophomore year at Waynesburg, Miller was diagnosed with Type 1 diabetes, a condition he has managed throughout his baseball career. He grew up as a fan of the Pittsburgh Pirates.

Path to Professional Baseball

Miller’s collegiate career at Waynesburg University and Gardner-Webb University prepared him for professional baseball. His impressive college performances caught the attention of MLB scouts, leading to his selection in the 2021 MLB Draft.

Mason James Miller Career

Early Career (2021–2022)

The Oakland Athletics selected Miller in the third round of the 2021 MLB Draft. He made his professional debut that same year with the Arizona Complex League Athletics. In 2022, Miller pitched in only six games across three levels, including the ACL Athletics, Lansing Lugnuts, and Las Vegas Aviators. After the season, he played in the Arizona Fall League to gain additional experience.

Oakland Athletics Breakthrough (2023–2025)

Miller began the 2023 season with the Double-A Midland RockHounds. After one start, he was promoted to Triple-A Las Vegas Aviators. On April 18, 2023, after recording 11 strikeouts over five perfect innings, the Athletics announced his promotion to the major leagues. He made his MLB debut on April 19, 2023, against the Chicago Cubs, pitching 4 and one-third innings with five strikeouts. Miller became the 10th starting pitcher since the debut of Statcast to throw 15 pitches above 100 miles per hour. However, he was later diagnosed with a mild sprain of the ulnar collateral ligament in his throwing elbow and did not return until September 6, when he was activated for a relief role. He finished the 2023 season with a 3.78 ERA in 10 games.

In 2024, the Athletics announced Miller would work exclusively as a reliever to manage his health. Beginning the season as the team’s closer, he earned his first career save on April 9 in a 4-3 win at Texas. Miller was named MLB Reliever of the Month for April 2024 after converting eight consecutive save opportunities with 28 strikeouts. On July 7, 2024, he was named a reserve player for the 2024 MLB All-Star Game, having recorded a 2.39 ERA with 14 saves and 66 strikeouts, leading all American League relievers. During the All-Star Game, he recorded a scoreless fifth inning with two strikeouts and earned the win as the American League defeated the National League 5-3. He threw the fastest pitch in All-Star Game history at 103.6 miles per hour to Trea Turner during that appearance. On September 26, 2024, Miller became the last pitcher to throw a pitch at Oakland Coliseum in a major league game, closing out the 3-2 victory over the Texas Rangers and setting the franchise record for saves by a rookie with 28. He also threw the fastest pitch ever recorded at the Coliseum at 103.8 miles per hour. Miller finished the 2024 season with a 2.49 ERA, 28 saves, and 104 strikeouts across 55 games. He was named to the All-MLB Second Team and finished fourth in AL Rookie of the Year voting.

San Diego Padres Era (2025–Present)

On July 31, 2025, the Athletics traded Miller to the San Diego Padres in exchange for Leo De Vries, Braden Nett, Eduarniel Nunez, and Henry Baez. On August 6, 2025, Miller recorded his first save as a Padre, striking out all three batters in the ninth inning to close out a 3-2 victory over the Arizona Diamondbacks. On September 3, 2025, Miller became just the second Padre to pitch an immaculate inning, striking out three consecutive batters on nine consecutive sliders against the Baltimore Orioles. For the 2025 season combined between both teams, he recorded a 2.63 ERA with 22 saves and 104 strikeouts across 60 games. With the Padres specifically, he posted a remarkable 0.77 ERA with two saves and 45 strikeouts in 23 and one-third innings.

Driving Style and Strengths

Miller is renowned for his elite fastball velocity, consistently pitching at triple digits. His high-velocity offerings have set multiple records, including the fastest pitch in All-Star Game history. He has also developed a devastating slider that he used to record an immaculate inning in 2025.

Notable Events and Milestones

Among his most significant career moments, Miller’s debut in April 2023 announced his arrival as a power pitcher. His 2024 All-Star selection highlighted his dominance as a reliever. The final pitch at Oakland Coliseum marked the end of an era. In 2026, he broke the Padres franchise record for consecutive scoreless innings at 34 and two-thirds innings.

Mason James Miller Career Wins

Miller has established himself as one of the premier relief pitchers in Major League Baseball, accumulating 71 career saves across his time with the Oakland Athletics and San Diego Padres. His career win-loss record stands at 5-8 with a 2.45 earned run average and 312 total strikeouts through June 2026.

San Diego Padres Highlights

Since joining the Padres in July 2025, Miller has been dominant in the closer role. His 2025 performance with the team featured a 0.77 ERA and two saves in three opportunities, including his first save as a Padre on August 6, 2025. The highlight of his early Padres career came on September 3, 2025, when he threw an immaculate inning against the Baltimore Orioles, striking out three batters on nine consecutive sliders.

Oakland Athletics Highlights

Miller saved his best season for his rookie year with the Athletics in 2024. He recorded 28 saves, setting the franchise rookie record while posting a 2.49 ERA with 104 strikeouts. He earned MLB Reliever of the Month honors in April and was selected to his first All-Star Game. His 2023 rookie season was shortened by injury but still showed promise with his debut performance featuring five strikeouts and multiple triple-digit fastballs.

Other Wins and Performances

Beyond his save totals, Miller’s career includes numerous high-leverage appearances. His scoreless inning during the 2024 All-Star Game helped secure the American League victory. His record-setting consecutive scoreless innings streak in 2026, reaching 34 and two-thirds, stands as the eighth-longest by a relief pitcher since the expansion era began in 1961.

Mason James Miller Family

Family Background and Racing Lineage

No verified information about Miller’s parents or family background is available in the public record.

Personal Life

Miller is a Christian and credits his faith as an important part of his life. He is married to Jordan Miller. He earned the rank of Eagle Scout, demonstrating his commitment to leadership and community service from a young age.

2025 Season Performance

The 2025 season marked a transformative year for Miller. He began the year with the Oakland Athletics and recorded the team’s first save at Sutter Health Park in Sacramento on April 12, 2025. On July 31, 2025, he was traded to the San Diego Padres as part of a multi-player deal. His transition to the Padres was seamless, as he recorded a 0.77 ERA with 45 strikeouts in 23 and one-third innings with his new team. He achieved his first save as a Padre on August 6, striking out the side. The highlight of his season came on September 3, 2025, when he threw an immaculate inning against the Baltimore Orioles, recording three strikeouts on nine consecutive sliders. Combined between both teams, Miller finished the 2025 season with a 2.63 ERA, 22 saves, and 104 strikeouts across 60 games. He made his postseason debut in Game 1 of the 2025 NL Wild Card Series against the Chicago Cubs, striking out all three batters he faced in the seventh inning.